One vertex per element, one color per generator, with an edge from x to x·s.
(2,3)(5,6)(7,11)(8,16)(9,18)(10,12)(13,19)(14,17)(15,20)(24,32)(26,34)(28,33)(31,36) involution — undirected(1,2,4,3)(5,7,10,15)(6,11,12,20)(8,17,18,13)(9,19,16,14)(21,22)(23,29)(24,33)(25,27)(26,31)(28,32)(30,35)(34,36)(5,8,16,6,10,18,9,12)(7,13,19,11,15,17,14,20)(21,23)(22,26,27,34)(24,31)(25,30)(28,29,33,35)(32,36)(1,3,4,2)(23,30)(26,34)(29,35)(31,36)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.